Autothermal reformer

Abstract

An autothermal reformer for converting a fuel into a reformate stream comprising hydrogen comprises (a) a closed vessel having a top end and a bottom end, the vessel comprising at least one insulation layer adjacent the interior surface of the vessel; (b) a first reactant manifold disposed within the vessel for receiving and distributing a first reactant stream, the first reactant manifold having a plurality of mixer tubes extending therefrom, each of the mixer tubes having an inlet end and an outlet end, the mixer tubes disposed in a separator member; and (c) a second reactant manifold disposed within the vessel for receiving and distributing a second reactant stream, the second reactant manifold comprising a plurality of injection tubes. Each of the injection tubes has an inlet end and an outlet end, extend through the first reactant manifold and are fluidly isolated therefrom. The outlet end of each of the plurality of injection tubes extends into the inlet end of one of the mixer tubes, thereby forming a gap between the outer wall of the injection tube and the inner wall of the mixer tube. Methods of operating the present autothermal reformer are also provided.

What is claimed is:  
     
       1. An autothermal reformer for converting reactants comprising a fuel and an oxidant into a reformate stream comprising hydrogen, said reformer comprising: 
       (a) a closed vessel, said vessel having a top end and a bottom end, said vessel comprising at least one insulation layer adjacent the interior surface of said vessel;  
       (b) a first reactant manifold disposed within said vessel for receiving and distributing a first reactant stream comprising one of said fuel and said oxidant, said first reactant manifold having a plurality of mixer tubes extending therefrom, each of said mixer tubes having an inlet end and an outlet end, said mixer tubes disposed in a separator member;  
       (c) a second reactant manifold disposed within said vessel for receiving and distributing a second reactant stream comprising the other of said fuel and said oxidant, said second reactant manifold comprising a plurality of injection tubes, each of said injection tubes having an inlet end and an outlet end, said injection tubes extending through said first reactant manifold and fluidly isolated therefrom; and  
       (d) a reforming section disposed within said vessel for receiving and converting said first and second reactant streams to a reformate stream comprising hydrogen;  
       wherein said outlet end of each of said plurality of injection tubes extends into said inlet end of one of said mixer tubes, thereby forming a gap between said outer wall of said injection tube and said inner wall of said mixer tube. 
     
     
       2. The reformer of  claim 1  wherein said first reactant stream comprises said fuel. 
     
     
       3. The reformer of  claim 1  wherein said first reactant stream comprises said oxidant. 
     
     
       4. The reformer of  claim 1  wherein said plurality of injection tubes and said mixer tubes are arranged in a hexagonal array. 
     
     
       5. The reformer of  claim 1  wherein the length of said mixer tubes is at least ten times the inner diameter of said mixer tubes. 
     
     
       6. The reformer of  claim 1  wherein said mixer tubes comprise openings in said separator member and cooperating openings in one end of said first reactant manifold. 
     
     
       7. The reformer of  claim 1  wherein said separator member comprises insulating material. 
     
     
       8. The reformer of  claim 7  wherein said insulating material comprises ceramic. 
     
     
       9. The reformer of  claim 1  wherein said gap is an annular gap. 
     
     
       10. The reformer of  claim 1 , wherein said reforming section comprises a combustion and gasification catalyst bed spaced apart from and in fluid communication with said separator member, and a steam reforming catalyst bed in contact with said combustion and gasification catalyst bed, and said separator member and said combustion and gasification catalyst bed form a plenum therebetween. 
     
     
       11. The reformer of  claim 10  wherein said combustion and gasification catalyst bed comprises at least one monolith comprising noble metal catalyst components disposed on a porous support. 
     
     
       12. The reformer of  claim 11  wherein said support comprises a ceramic honeycomb. 
     
     
       13. The reformer of  claim 10  wherein said steam reforming catalyst bed comprises at least one monolith comprising noble metal catalyst components disposed on a porous support. 
     
     
       14. The reformer of  claim 13  wherein said support comprises a ceramic honeycomb. 
     
     
       15. The reformer of  claim 10  wherein said plenum is at least partially filled with a particulate combustion and gasification catalyst. 
     
     
       16. The reformer of  claim 15  wherein said particulate combustion and gasification catalyst comprises noble metal catalyst components disposed on a pelletized porous support. 
     
     
       17. The reformer of  claim 10 , further comprising a first heat exchange member disposed within said vessel and in thermal communication with said reformate stream, said first heat exchange member receiving a steam stream and superheating said stream therein by heat exchange with said reformate stream. 
     
     
       18. The reformer of  claim 17  wherein said first heat exchange member comprises a helical coil. 
     
     
       19. The reformer of  claim 18  wherein said helical coil comprises a bare helical coil disposed within a high temperature alloy steel metal annulus packed with high-temperature metal heat transfer packing. 
     
     
       20. The reformer of  claim 19  wherein said packing comprises high void fraction pall rings or saddles. 
     
     
       21. The reformer of  claim 10 , further comprising a heat exchange member disposed within said vessel and in thermal communication with said reformate stream, said heat exchange member receiving a feed stream comprising water and vaporizing said feed stream therein by heat exchange with said reformate stream to produce a steam stream. 
     
     
       22. The reformer of  claim 21  wherein said heat exchange member comprises a helical coil. 
     
     
       23. The reformer of  claim 22  wherein said helical coil comprises a finned tube helical coil disposed within an alloy steel sheet metal annulus. 
     
     
       24. The reformer of  claim 17 , further comprising a second heat exchange member disposed within said vessel and fluidly connected to said first heat exchange member and in thermal communication with said reformate stream, said second heat exchange member receiving a feed stream comprising water and vaporizing said feed stream therein by heat exchange with said reformate stream to produce said steam stream. 
     
     
       25. The reformer of  claim 24  wherein said second heat exchange member comprises a helical coil. 
     
     
       26. The reformer of  claim 25  wherein said helical coil comprises a finned tube helical coil disposed within an alloy steel sheet metal annulus. 
     
     
       27. The reformer of  claim 1 , further comprising a fuel vaporizer disposed within said vessel and fluidly connected to one of said first and second reactant manifolds, said fuel vaporizer comprising a helical coil. 
     
     
       28. The reformer of  claim 10 , further comprising a fuel vaporizer disposed within said vessel and fluidly connected to one of said first and second reactant manifolds, said fuel vaporizer comprising a helical coil. 
     
     
       29. The reformer of  claim 17 , further comprising a fuel vaporizer disposed within said vessel and comprising a helical coil, said fuel vaporizer fluidly connected to said first heat exchange member for receiving a steam stream therefrom and fluidly connected to one of said first and second reactant manifolds. 
     
     
       30. The reformer of  claim 21 , further comprising a fuel vaporizer disposed within said vessel and fluidly connected to one of said first and second reactant manifolds, said fuel vaporizer comprising a helical coil. 
     
     
       31. The reformer of  claim 24 , further comprising a fuel vaporizer disposed within said vessel and comprising a helical coil, said fuel vaporizer fluidly connected to said first heat exchange member for receiving a steam stream therefrom, and fluidly connected to one of said first and second reactant manifolds. 
     
     
       32. The reformer of  claim 24  wherein said vessel comprises heat exchange members associated with the external surface of said vessel for flowing a heat exchange fluid therethrough. 
     
     
       33. The reformer of  claim 32  wherein said heat exchange members comprise plate coil or helical coil. 
     
     
       34. The reformer of  claim 33  wherein said heat exchange fluid comprises said feed stream. 
     
     
       35. The reformer of  claim 32  wherein said vessel further comprises an external insulating layer adjacent the exterior surface of said vessel. 
     
     
       36. The reformer of  claim 31  wherein said vessel comprises heat exchange members associated with the external surface of said vessel for flowing a heat exchange fluid therethrough. 
     
     
       37. The reformer of  claim 36  wherein said heat exchange members comprise plate coil or helical coil. 
     
     
       38. The reformer of  claim 37  wherein said heat exchange fluid comprises said feed stream. 
     
     
       39. The reformer of  claim 36  wherein said vessel further comprises an external insulating layer adjacent the exterior surface of said vessel.